Eupafolin ameliorates COX-2 expression and PGE2 production in particulate pollutants-exposed human keratinocytes through ROS/MAPKs pathways

Air Pollution and Skin Diseases

Air pollution is a widespread environmental issue, with substantial global implications for human health. Recent epidemiological studies have shown that exposure to air pollution exacerbates various inflammatory skin conditions, including atopic dermatitis, psoriasis, or acne. Furthermore, air pollutants are associated with accelerated skin aging, hair loss, and skin cancer. The aim of this review is to elucidate the current understanding of the impact of air pollution on skin health, emphasizing the underlying mechanisms involved and existing therapeutic and cosmetic interventions available to prevent or mitigate these effects. A pivotal factor in the harmful effects of air pollution is the formation of reactive oxygen species and the resulting oxidative stress. The aryl hydrocarbon receptor signaling pathway also substantially contributes to mediating the effects of air pollutants on various skin conditions. Moreover, air pollutants can disrupt the skin barrier function and trigger inflammation. Consequently, antioxidant and anti-inflammatory therapies, along with treatments designed to restore the skin barrier function, have the potential to mitigate the adverse effects of air pollutants on skin health.

Therapeutic Potential of Herbal Medicines in Combating Particulate Matter (PM)-Induced Health Effects: Insights from Recent Studies

Particulate matter (PM), particularly fine (PM2.5) and ultrafine (PM0.1) particles, originates from both natural and anthropogenic sources, such as biomass burning and vehicle emissions. These particles contain harmful compounds that pose significant health risks. Upon inhalation, ingestion, or dermal contact, PM can penetrate biological systems, inducing oxidative stress, inflammation, and DNA damage, which contribute to a range of health complications. This review comprehensively examines the protective potential of natural products against PM-induced health issues across various physiological systems, including the respiratory, cardiovascular, skin, neurological, gastrointestinal, and ocular systems. It provides valuable insights into the health risks associated with PM exposure and highlights the therapeutic promise of herbal medicines by focusing on the natural products that have demonstrated protective properties in both in vitro and in vivo PM2.5-induced models. Numerous herbal medicines and phytochemicals have shown efficacy in mitigating PM-induced cellular damage through their ability to counteract oxidative stress, suppress pro-inflammatory responses, and enhance cellular defense mechanisms. These combined actions collectively protect tissues from PM-related damage and dysfunction. This review establishes a foundation for future research and the development of effective interventions to combat PM-related health issues. However, further studies, including in vivo and clinical trials, are essential to evaluate the safety, optimal dosages, and long-term effectiveness of herbal treatments for patients under chronic PM exposure.

Broccoli Sprout Extract Suppresses Particulate-Matter-Induced Matrix-Metalloproteinase (MMP)-1 and Cyclooxygenase (COX)-2 Expression in Human Keratinocytes by Direct Targeting of p38 MAP Kinase

BACKGROUND/OBJECTIVES

Particulate matter (PM) is an environmental pollutant that negatively affects human health, particularly skin health. In this study, we investigated the inhibitory effects of broccoli sprout extract (BSE) on PM-induced skin aging and inflammation in human keratinocytes.

METHODS

HaCaT keratinocytes were pretreated with BSE before exposure to PM. Cell viability was assessed using the MTT assay. The expression of skin aging and inflammation markers (MMP-1, COX-2, IL-6) was measured using Western blot, ELISA, and qRT-PCR. Reactive oxygen species levels were determined using the DCF-DA assay. Kinase assays and pull-down assays were conducted to investigate the interaction between BSE and p38α MAPK.

RESULTS

Our findings demonstrate that BSE effectively suppressed the expression of MMP-1, COX-2, and IL-6-critical skin aging and inflammation markers-by inhibiting p38 MAPK activity. BSE binds directly to p38α without competing with ATP, thereby selectively inhibiting its activity and downstream signaling pathways, including MSK1/2, AP-1, and NF-κB.

CONCLUSIONS

These results suggest that BSE is a potential functional ingredient in skincare products to mitigate PM-induced skin damage.

Specialized pro-resolving mediator 7S MaR1 inhibits IL-6 expression via modulating ROS/p38/ERK/NF-κB pathways in PM10-exposed keratinocytes

Keratinocytes are susceptible to airborne particulate matter (PM) exposure, resulting in human skin barrier dysfunction. Therefore, it is important to find useful reagents to resolve skin damages caused by PM. Here, we explored the protective effect of 7S MaR1, a specialized pro-resolving mediator derived from docosahexaenoic acid, on skin inflammation and the oxidative stress induced by PM with a diameter 10 μm or less (PM10) in human keratinocyte HaCaT cells. Interestingly, PM10-induced ROS generation was modulated by 7S MaR1 via the recovery of ROS scavenger genes. 7S MaR1 reduced PM10-induced IL-6 expression via modulating the p38/ERK/NF-κB signaling pathways. These results demonstrate that PM10 induces inflammatory cytokines, which can lead to skin diseases. In addition, 7S MaR1 can resolve inflammation caused by PM10-induced oxidative stress and inflammatory cytokines. [BMB Reports 2024; 57(11): 490-496].

Network pharmacology-based approach to investigate the molecular targets and molecular mechanisms of Rosmarinus officinalis L. for treating aging-related disorders

Aging, a natural biological process, presents challenges in maintaining physiological well-being and is associated with increased vulnerability to diseases. Addressing aging mechanisms is crucial for developing effective preventive and therapeutic strategies against age-related ailments. Rosmarinus officinalis L. is a medicinal herb widely used in traditional medicine, containing diverse bioactive compounds that have been studied for their antioxidant and anti-inflammatory properties, which are associated with potential health benefits. Using network pharmacology, this study investigates the anti-aging function and underlying mechanisms of R. officinalis. Through network pharmacology analysis, the top 10 hub genes were identified, including TNF, CTNNB1, JUN, MTOR, SIRT1, and others associated with the anti-aging effects. This analysis revealed a comprehensive network of interactions, providing a holistic perspective on the multi-target mechanism underlying Rosemary's anti-aging properties. GO and KEGG pathway enrichment analysis revealed the relevant biological processes, molecular functions, and cellular components involved in treating aging-related conditions. KEGG pathway analysis shows that anti-aging targets of R. officinalis involved endocrine resistance, pathways in cancer, and relaxin signaling pathways, among others, indicating multifaceted mechanisms. Genes like MAPK1, MMP9, and JUN emerged as significant players. These findings enhance our understanding of R. officinalis's potential in mitigating aging-related disorders through multi-target effects on various biological processes and pathways. Such approaches may reduce the risk of failure in single-target and symptom-based drug discovery and therapy.

Particulate Matter and Its Molecular Effects on Skin: Implications for Various Skin Diseases

Particulate matter (PM) is a harmful air pollutant composed of chemicals and metals which affects human health by penetrating both the respiratory system and skin, causing oxidative stress and inflammation. This review investigates the association between PM and skin disease, focusing on the underlying molecular mechanisms and specific disease pathways involved. Studies have shown that PM exposure is positively associated with skin diseases such as atopic dermatitis, psoriasis, acne, and skin aging. PM-induced oxidative stress damages lipids, proteins, and DNA, impairing cellular functions and triggering inflammatory responses through pathways like aryl hydrocarbon receptor (AhR), NF-κB, and MAPK. This leads to increased production of inflammatory cytokines and exacerbates skin conditions. PM exposure exacerbates AD by triggering inflammation and barrier disruption. It disrupts keratinocyte differentiation and increases pro-inflammatory cytokines in psoriasis. In acne, it increases sebum production and inflammatory biomarkers. It accelerates skin aging by degrading ECM proteins and increasing MMP-1 and COX2. In conclusion, PM compromises skin health by penetrating skin barriers, inducing oxidative stress and inflammation through mechanisms like ROS generation and activation of key pathways, leading to cellular damage, apoptosis, and autophagy. This highlights the need for protective measures and targeted treatments to mitigate PM-induced skin damage.

Evaluation of the amelioration effect of Ganoderma formosanum extract on delaying PM2.5 damage to lung macrophages

SCOPE

Particulate matter (PM) contains toxic organic matter and heavy metals that enter the entire body through blood flow and may cause mortality. Ganoderma formosanum mycelium, a valuable traditional Chinese medicine that has been used since ancient times, contains various active ingredients that can effectively impede inflammatory responses on murine alveolar macrophages induced by PM particles.

METHODS AND RESULTS

An experimental study assessing the effect of G. formosanum mycelium extract's water fraction (WA) on PM-exposed murine alveolar macrophages using ROS measurement shows that WA reduces intracellular ROS by 12% and increases cell viability by 16% when induced by PM particles. According to RNA-Sequencing, western blotting, and real-time qPCR are conducted to analyze the metabolic pathway. The WA reduces the protein ratio in p-NF-κB/NF-κB by 18% and decreases the expression of inflammatory genes, including IL-1β by 38%, IL-6 by 29%, and TNF-α by 19%. Finally, the identification of seven types of anti-inflammatory compounds in the WA fraction is achieved through UHPLC-ESI-Orbitrap-Elite-MS/MS analysis. These compounds include anti-inflammatory compounds, namely thiamine, adenosine 5'-monophosphate, pipecolic acid, L-pyroglutamic acid, acetyl-L-carnitine, D-mannitol, and L-malic acid.

CONCLUSIONS

The study suggests that the WA has the potential to alleviate the PM -induced damage in alveolar macrophages, demonstrating its anti-inflammatory properties.

Exploration of natural flavones' bioactivity and bioavailability in chronic inflammation induced-type-2 diabetes mellitus

Diabetes, being the most widespread illness, poses a serious threat to global public health. It seems that inflammation plays a critical role in the pathophysiology of diabetes. This review aims to demonstrate a probable link between type 2 diabetes mellitus (T2DM) and chronic inflammation during its development. Additionally, the current review examined the bioactivity of natural flavones and the possible molecular mechanisms by which they influence diabetes and inflammation. While natural flavones possess remarkable anti-diabetic and anti-inflammatory bioactivities, their therapeutic use is limited by the low oral bioavailability. Several factors contribute to the low bioavailability, including poor water solubility, food interaction, and unsatisfied metabolic behaviors, while the diseases (diabetes, inflammation, etc.) causing even less bioavailability. Throughout the years, different strategies have been developed to boost flavones' bioavailability, including structural alteration, biological transformation, and innovative drug delivery system design. This review addresses current advancements in improving the bioavailability of flavonoids in general, and flavones in particular. Clinical trials were also analyzed to provide insight into the potential application of flavonoids in diabetes and inflammatory therapies.

Protocatechuic Acid and Syringin from Saussurea neoserrata Nakai Attenuate Prostaglandin Production in Human Keratinocytes Exposed to Airborne Particulate Matter

Saussurea neoserrata Nakai offers a reliable and efficient source of antioxidants that can help alleviate adverse skin reactions triggered by air pollutants. Air pollutants, such as particulate matter (PM), have the ability to infiltrate the skin and contribute to the higher occurrence of cardiovascular, cerebrovascular, and respiratory ailments. Individuals with compromised skin barriers are particularly susceptible to the impact of PM since it can be absorbed more readily through the skin. This study investigated the impact of protocatechuic acid and syringin, obtained from the n-BuOH extract of S. neoserrata Nakai, on the release of PGE₂ and PGD₂ induced by PM₁₀. Additionally, it examined the gene expression of the synthesis of PGE₂ and PGD₂ in human keratinocytes. The findings of this research highlight the potential of utilizing safe and efficient plant-derived antioxidants in dermatological and cosmetic applications to mitigate the negative skin reactions caused by exposure to air pollution.

Aryl Hydrocarbon Receptor as a Therapeutical Target of Environmentally Induced Skin Conditions

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor, expressed in several tissues and involved in the response to environmental stressors. Studies have already associated exposure to environmental factors, such as organic air pollutants, products of the skin microbiota, and solar radiation, with the development/worsening of skin conditions, mediated by AhR. On the other hand, recent studies have shown that synthetic and natural compounds are able to modulate the activation of some AhR signaling pathways, minimizing the harmful response of these environmental stressors in the skin. Thus, AhR constitutes a new therapeutic target for the prevention or treatment of skin conditions induced by the skin exposome. Herein, an overview of potential AhR ligands and their biologic effects in environmentally induced skin conditions are presented. The literature survey pointed out divergences in the mechanism of action from a therapeutic perspective. Although most studies point to the benefits of ligand downregulation of AhR signaling, counteracting the toxic effects of environmental factors on the skin, some studies suggest the AhR ligand activation as a therapeutical mechanism for some skin conditions. Furthermore, both agonist and antagonist profiles were identified in the AhR modulation by the synthetic and natural compounds raised. Despite that, this target is still little explored, and further studies are needed to elucidate the molecular mechanisms involved and identify new AhR ligands with therapeutic potential. SIGNIFICANCE STATEMENT: The aryl hydrocarbon receptor (AhR) is involved in different skin physiological and pathological processes, including toxic mechanisms of environmental factors. Synthetic and natural AhR ligands have demonstrated therapeutic potential for skin conditions induced by these agents. Thus, a comprehensive understanding of the skin toxicity mechanisms involving the AhR, as well as the use of AhR modulators from a therapeutic perspective, provides an alternative approach to the development of new treatments for skin disorders induced by the exposome.

Chlorogenic Acid, a Component of Oenanthe javanica (Blume) DC., Attenuates Oxidative Damage and Prostaglandin E2 Production Due to Particulate Matter 10 in HaCaT Keratinocytes

Oenanthe javanica (OJ) is a perennial herb that grows wildly or is cultivated in Asia, and it is used as food or in traditional medicine. The antioxidant and anti-inflammatory effects of OJ-derived materials have been extensively explored previously, but their effects on the cytotoxicity of air pollution are currently unknown. Therefore, the present study aimed to evaluate the effect of the hot water extract of OJ on atmospheric particulate matter 10 (PM10)-induced cytotoxicity and oxidative damage in human HaCaT keratinocytes, and to identify its active ingredient and mechanism of action. When the hot water extract of OJ was divided into methylene chloride, ethyl acetate (EA), n-butanol (BA), and water fractions, caffeic acid was enriched in the EA fraction and chlorogenic acid was enriched in the BA fraction. PM10 increased reactive oxygen species (ROS) production, lipid peroxidation, protein carbonylation, and inflammatory prostaglandin (PG) E2 production in cells. The BA fraction reduced the PM10-induced ROS production in cells more effectively than the total extract and other solvent fractions. Chlorogenic acid was more effective in reducing ROS levels than caffeic acid and N-acetyl cysteine (NAC). Chlorogenic acid attenuated the increase in lipid peroxidation and the PG E2 production of cells due to PM10 exposure. Of the genes involved in PG E2 production, phospholipase A2 group IVA (PLA2G4A), Prostaglandin-endoperoxide synthase 1 (PTGS1), and 2 (PTGS2) were transcriptionally up-regulated by PM10, whereas phospholipase A2 group IIA (PLA2G2A) was down-regulated and prostaglandin E synthetase 1 (PTGES1) and 2 (PTGES2) were a little altered. The PM10-induced increase in PLA2G4A mRNA was alleviated by chlorogenic acid and NAC. Accordingly, PM10 increased the expression levels of cytosolic phospholipase A2 (cPLA2) protein and its phosphorylated form, which were attenuated by chlorogenic acid and NAC. Thus, chlorogenic acid may attenuate the PM10-induced PG E2 production through the suppression of PLA2G4A mRNA and cPLA2 protein expressions. This study suggests that chlorogenic acid contained in OJ extract may help alleviate the oxidative damage to and inflammatory responses of the skin cells due to exposure to air pollutants.

AuAg nanocomposites suppress biofilm-induced inflammation in human osteoblasts

Staphylococcus aureus (S. aureus)forms biofilm that causes periprosthetic joint infections and osteomyelitis (OM) which are the intractable health problems in clinics. The silver-containing nanoparticles (AgNPs) are antibacterial nanomaterials with less cytotoxicity than the classic Ag compounds. Likewise, gold nanoparticles (AuNPs) have also been demonstrated as excellent nanomaterials for medical applications. Previous studies have showed that both AgNPs and AuNPs have anti-microbial or anti-inflammatory properties. We have developed a novel green chemistry that could generate the AuAg nanocomposites, through the reduction of tannic acid (TNA). The bioactivity of the nanocomposites was investigated inS. aureusbiofilm-exposed human osteoblast cells (hFOB1.19). The current synthesis method is a simple, low-cost, eco-friendly, and green chemistry approach. Our results showed that the AuAg nanocomposites were biocompatible with low cell toxicity, and did not induce cell apoptosis nor necrosis in hFOB1.19 cells. Moreover, AuAg nanocomposites could effectively inhibited the accumulation of reactive oxygen species (ROS) in mitochondria and in rest of cellular compartments after exposing to bacterial biofilm (by reducing 0.78, 0.77-fold in the cell and mitochondria, respectively). AuAg nanocomposites also suppressed ROS-triggered inflammatory protein expression via MAPKs and Akt pathways. The current data suggest that AuAg nanocomposites have the potential to be a good therapeutic agent in treating inflammation in bacteria-infected bone diseases.

Nanoparticles for Topical Application in the Treatment of Skin Dysfunctions-An Overview of Dermo-Cosmetic and Dermatological Products

Nanomaterials (NM) arouse interest in various fields of science and industry due to their composition-tunable properties and the ease of modification. They appear currently as components of many consumer products such as sunscreen, dressings, sports clothes, surface-cleaning agents, computer devices, paints, as well as pharmaceutical and cosmetics formulations. The use of NPs in products for topical applications improves the permeation/penetration of the bioactive compounds into deeper layers of the skin, providing a depot effect with sustained drug release and specific cellular and subcellular targeting. Nanocarriers provide advances in dermatology and systemic treatments. Examples are a non-invasive method of vaccination, advanced diagnostic techniques, and transdermal drug delivery. The mechanism of action of NPs, efficiency of skin penetration, and potential threat to human health are still open and not fully explained. This review gives a brief outline of the latest nanotechnology achievements in products used in topical applications to prevent and treat skin diseases. We highlighted aspects such as the penetration of NPs through the skin (influence of physical-chemical properties of NPs, the experimental models for skin penetration, methods applied to improve the penetration of NPs through the skin, and methods applied to investigate the skin penetration by NPs). The review summarizes various therapies using NPs to diagnose and treat skin diseases (melanoma, acne, alopecia, vitiligo, psoriasis) and anti-aging and UV-protectant nano-cosmetics.

Phenolic fingerprints of the Pacific seagrass Phyllospadixtorreyi - Structural characterization and quantification of undescribed flavonoid sulfates

Four undescribed flavonoid sulfates were isolated from Phyllospadix torreyi S. Watson foliar tissue. In addition, nine known flavonoid sulfates and three phenolic acids were isolated from the same extract, of which seven had never been reported for the genus Phyllospadix. Structural elucidation of individual phenolics was assigned using complementary informations from their spectral evidence (HPLC-DAD, LC-MS, NMR, and UV) and chemical behavior. The inter-annual variation in phenolic concentrations was determined by quantitative HPLC-DAD over a three-year period. The results showed a relative constancy of phenolic content over time and the high prevalence of flavonoid disulfates (70-90% of the total flavonoids detected). All samples were found dominated by the unreported nepetin 7, 3'-disulfate and 5-methoxyluteolin 7, 3'-disulfate, followed by luteolin 7, 3'-disulfate. Considering the economic potential of flavonoid sulfates in the pharmaceutical and nutraceutical segments, a sample of detrital leaves was also analyzed. The same phenolic pattern was found and the concentration of the individuals, although lower than in fresh material, makes this abundant biomass of interest for dietary and pharmaceutical applications.

The Effect of Urban Green Spaces on Reduction of Particulate Matter Concentration

In an urban scenario, one of the air pollutants most harmful to human health and environmental is the particulate matter (PM). Considering that urban green areas can contribute to mitigating the effects of PM, this work compares the concentration of PM_2.5 in two closer locations in Rio de Janeiro, in order to verify how vegetation cover can actually improve air quality. One is the entrance to the Rebouças Tunnel (RT) and the other is the Rio de Janeiro Botanical Garden (RJBG). For this purpose, PM_2.5 samples were taken from September 2017 to March 2018 using a Large Volume Sampler (LVS). The results reveal that RT has a higher concentration of PM_2.5 in almost all samples. The RJBG obtains concentrations around 33% less than the other area, suggesting that the presence of urban green areas like the RJBG can reduce PM_2.5 levels when compared to places with less vegetation cover, providing better air quality.

Anticonvulsive and Neuroprotective Effects of Eupafolin in Rats Are Associated with the Inhibition of Glutamate Overexcitation and Upregulation of the Wnt/β-Catenin Signaling Pathway

Several plant compounds have been found to possess neuroactive properties. The aim of this study was to investigate the anticonvulsant effect of eupafolin, a major active component extracted from Salvia plebeia, a herb used in traditional medicine for its anti-inflammatory properties. To this end, we assessed the anticonvulsant effects of eupafolin in rats intraperitoneally (i.p.) injected with kainic acid (KA) to elucidate this mechanism. Treatment with eupafolin (i.p.) for 30 min before KA administration significantly reduced behavioral and electrographic seizures induced by KA, similar to carbamazepine (i.p.), a widely used antiepileptic drug. Eupafolin treatment also significantly decreased KA seizure-induced neuronal cell death and glutamate elevation in the hippocampus. In addition, eupafolin notably reversed KA seizure-induced alterations in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subunit GluR2, glutamate decarboxylase 67 (GAD67, GABAergic enzyme), and Wnt signaling-related proteins, including porcupine, Wnt1, phosphorylated-glycogen synthase kinase-3β, β-catenin, and Bcl-2 in the hippocampus. Furthermore, the increased level of Dickkopf-related protein 1 (Dkk-1, a Wnt signaling antagonist) and the decreased level of Disheveled1 (Dvl-1, a Wnt signaling activator) in the hippocampus of KA-treated rats were reversed by eupafolin. This study provides evidence of the anticonvulsant and neuroprotective properties of eupafolin and of the involvement of regulation of glutamate overexcitation and Wnt signaling in the mechanisms of these properties. These findings support the benefits of eupafolin in treating epilepsy.

Antioxidant Effects of Korean Propolis in HaCaT Keratinocytes Exposed to Particulate Matter 10

Air pollution causes oxidative stress that leads to inflammatory diseases and premature aging of the skin. The purpose of this study was to examine the antioxidant effect of Korean propolis on oxidative stress in human epidermal HaCaT keratinocytes exposed to particulate matter with a diameter of less than 10 μm (PM₁₀). The total ethanol extract of propolis was solvent-fractionated with water and methylene chloride to divide into a hydrophilic fraction and a lipophilic fraction. The lipophilic fraction of propolis was slightly more cytotoxic, and the hydrophilic fraction was much less cytotoxic than the total extract. The hydrophilic fraction did not affect the viability of cells exposed to PM₁₀, but the total propolis extract and the lipophilic fraction aggravated the toxicity of PM₁₀. The total extract and hydrophilic fraction inhibited PM₁₀-induced ROS production and lipid peroxidation in a concentration-dependent manner, whereas the lipophilic fraction did not show such effects. High-performance liquid chromatography with photodiode array detection (HPLC-DAD) analysis showed that the hydrophilic fraction contained phenylpropanoids, such as caffeic acid, p-coumaric acid, and ferulic acid, whereas the lipophilic faction contained caffeic acid phenethyl ester (CAPE). The former three compounds inhibited PM₁₀-induced ROS production, lipid peroxidation, and/or glutathione oxidation, and ferulic acid was the most effective among them, but CAPE exhibited cytotoxicity and aggravated the toxicity of PM₁₀. This study suggests that Korean propolis, when properly purified, has the potential to be used as a cosmetic material that helps to alleviate the skin toxicity of air pollutants.

Siegesbeckiae Herba Extract and Chlorogenic Acid Ameliorate the Death of HaCaT Keratinocytes Exposed to Airborne Particulate Matter by Mitigating Oxidative Stress

Airborne particulate matter with a size of 10 μm or less (PM₁₀) can cause oxidative damages and inflammatory reactions in the skin. This study was conducted to discover natural products that are potentially useful in protecting the skin from PM₁₀. Among the hot water extracts of a total of 23 medicinal plants, Siegesbeckiae Herba extract (SHE), which showed the strongest protective effect against PM₁₀ cytotoxicity, was selected, and its mechanism of action and active constituents were explored. SHE ameliorated PM₁₀-induced cell death, lactate dehydrogenase (LDH) release, lipid peroxidation, and reactive oxygen species (ROS) production in HaCaT cells. SHE decreased the expression of KEAP1, a negative regulator of NRF2, and increased the expression of NRF2 target genes, such as HMOX1 and NQO1. SHE selectively induced the enzymes involved in the synthesis of GSH (GCL-c and GCL-m), the regeneration of GSH (GSR and G6PDH), and GSH conjugation of xenobiotics (GSTκ1), rather than the enzymes that directly scavenge ROS (SOD1, CAT, and GPX1). SHE increased the cellular content of GSH and mitigated the oxidation of GSH to GSSG caused by PM₁₀ exposure. Of the solvent fractions of SHE, the n-butyl alcohol (BA) fraction ameliorated cell death in both the absence and presence of PM₁₀. The BA fraction contained a high amount of chlorogenic acid. Chlorogenic acid reduced PM₁₀-induced cell death, LDH release, and ROS production. This study suggests that SHE protects cells from PM₁₀ toxicity by increasing the cellular antioxidant capacity and that chlorogenic acid may be an active phytochemical of SHE.

Eupafolin Suppresses P/Q-Type Ca2+ Channels to Inhibit Ca2+/ Calmodulin-Dependent Protein Kinase II and Glutamate Release at Rat Cerebrocortical Nerve Terminals

Eupafolin, a constituent of the aerial parts of Phyla nodiflora, has neuroprotective property. Because reducing the synaptic release of glutamate is crucial to achieving pharmacotherapeutic effects of neuroprotectants, we investigated the effect of eupafolin on glutamate release in rat cerebrocortical synaptosomes and explored the possible mechanism. We discovered that eupafolin depressed 4-aminopyridine (4-AP)-induced glutamate release, and this phenomenon was prevented in the absence of extracellular calcium. Eupafolin inhibition of glutamate release from synaptic vesicles was confirmed through measurement of the release of the fluorescent dye FM 1-43. Eupafolin decreased 4-AP-induced [Ca²⁺]_i elevation and had no effect on synaptosomal membrane potential. The inhibition of P/Q-type Ca²⁺ channels reduced the decrease in glutamate release that was caused by eupafolin, and docking data revealed that eupafolin interacted with P/Q-type Ca²⁺ channels. Additionally, the inhibition of calcium/calmodulin-dependent protein kinase II (CaMKII) prevented the effect of eupafolin on evoked glutamate release. Eupafolin also reduced the 4-AP-induced activation of CaMK II and the subsequent phosphorylation of synapsin I, which is the main presynaptic target of CaMKII. Therefore, eupafolin suppresses P/Q-type Ca²⁺ channels and thereby inhibits CaMKII/synapsin I pathways and the release of glutamate from rat cerebrocortical synaptosomes.

Pterostilbene Attenuates Particulate Matter-Induced Oxidative Stress, Inflammation and Aging in Keratinocytes

Particulate matter (PM) is the main indicator of air pollutants, and it may increase the level of reactive oxygen species (ROS) in keratinocytes, leading to skin inflammation, aging, and decreased moisturizing ability. Pterostilbene (PTS) is a dimethylated analog of resveratrol that has antioxidant effects. However, the molecular mechanisms of PTS in preventing PM-induced keratinocyte inflammation and aging have not been investigated yet. Therefore, we used PM-induced human keratinocytes to investigate the protective mechanisms of PTS. The results showed that 20 μM PTS had no toxicity to HaCaT keratinocytes and significantly reduced PM-induced intracellular ROS production. In addition, nuclear translocation of the aryl hydrocarbon receptor (AHR) was inhibited by PTS, leading to reduced expression of its downstream CYP1A1. PTS further inhibited PM-induced MAPKs, inflammation (COX-2), and aging (MMP-9) protein cascades, and rescued moisturizing (AQP-3) protein expression. We analyzed the PTS content in cells at different time points and compared the concentration required for PTS to inhibit the target proteins. Finally, we used the skin penetration assay to show that the PTS essence mainly exists in the epidermal layer and did not enter the system circulation. In conclusion, PTS could protect HaCaT keratinocytes from PM-induced damage and has the potential to become a cosmetic ingredient.

Nanoparticle platforms for dermal antiaging technologies: Insights in cellular and molecular mechanisms

Aging is a continuous process defined by a progressive functional decline in physiological parameters. Skin, being one of the most vulnerable organs, shows early signs of aging which are predominantly affected by intrinsic factors like hormone, gender, mood, enzymes, and genetic predisposition, and extrinsic factors like exposure to radiation, air pollution, and heat. Visible morphological and anatomical changes associated with skin aging occur due to underlying physiological aberrations governed by numerous complex interactions at cellular and subcellular levels. Nanoparticles are perceived as a powerful tool in the cosmeceutical industry both for augmenting the efficacy of existing agents and as a novel standalone therapy. Both organic and inorganic nanoparticles have been extensively investigated in antiaging applications. The use of nanoparticles helps to enhance the activity of antiaging molecules by selectively targeting cellular and molecular pathways. On the other hand, the nanoparticle platforms also gained increasing popularity as the skin protectant against extrinsic factors such as UV radiation and pollutants. This review comprehensively discusses skin aging and its mechanism by highlighting the impact on cellular, subcellular, and epigenetic elements. Importantly, the review elaborates on the examples of organic and inorganic nanoparticle-based formulations developed for antiaging application and provides mechanistic insights on how they modulate the mechanisms of skin aging. The clinical progress of nanoparticle antiaging technologies and factors that impact clinical translation are also explored. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Stevia Genus: Phytochemistry and Biological Activities Update

The Stevia genus (Asteraceae) comprises around 230 species, distributed from the southern United States to the South American Andean region. Stevia rebaudiana, a Paraguayan herb that produces an intensely sweet diterpene glycoside called stevioside, is the most relevant member of this genus. Apart from S. rebaudiana, many other species belonging to the Stevia genus are considered medicinal and have been popularly used to treat different ailments. The members from this genus produce sesquiterpene lactones, diterpenes, longipinanes, and flavonoids as the main types of phytochemicals. Many pharmacological activities have been described for Stevia extracts and isolated compounds, antioxidant, antiparasitic, antiviral, anti-inflammatory, and antiproliferative activities being the most frequently mentioned. This review aims to present an update of the Stevia genus covering ethnobotanical aspects and traditional uses, phytochemistry, and biological activities of the extracts and isolated compounds.

Natural compounds protect the skin from airborne particulate matter by attenuating oxidative stress

Particulate matter (PM) is a common indirect indicator of air pollution and threatens public health upon prolonged exposure, leading to oxidative stress, increasing the risk of develop respiratory and cardiovascular, as well as several autoimmune diseases and cancer. Nowadays, as a first line defense against PM, skin health attracted much attention. Our review summarized the skin damage mechanism induced by PM, including damage skin barrier directly, reactive oxygen species (ROS) accumulation, autophagy, and two canonical signaling pathways. Furthermore, ROS and oxidative stress have been considered pathogenesis centers, with essential skin damage roles. Extracts from plants and natural compounds which present high antioxidant capacity could be used to treat or protect against air pollution-related skin damage. We conclude the extracts reported in recent studies with protective effects on PM-mediated skin damage. Besides, the mechanism of extracts' positive effects has been revealed partially.

Negative Air Ions Alleviate Particulate Matter-Induced Inflammation and Oxidative Stress in the Human Keratinocyte Cell Line HaCaT

Background

Recent studies have revealed that particulate matter induces inflammation, oxidative stress, and several skin diseases. Experimental results have also shown that negative air ions are highly effective in removing particulate matter-induced inflammation.

Objective

The present study aimed to investigate whether negative air ions can inhibit inflammatory responses and reduce oxidative stress in HaCaT cells exposed to particulate matters.

Methods

HaCaT cells were treated with particulate matter in the presence or absence of negative air ions and the viability was evaluated by the MTT assay. Reactive oxygen species (ROS) generation was quantified by the dichlorodihydrofluorescein diacetate assay. The expression of genes and proteins was analyzed by real-time polymerase chain reaction and Western blot. Levels of inflammatory cytokines were quantified by enzyme-linked immunosorbent assay.

Results

Negative air ions were observed to downregulate the mRNA and protein levels of particulate matter-induced pro-inflammatory cytokines in HaCaT cells. In addition, negative air ion treatment suppressed particulate matter-induced intracellular ROS generation, p38 mitogen-activated protein kinase activation, and activator protein 1 (c-Fos and c-Jun) activation.

Conclusion

Our findings indicate that negative air ions exert anti-inflammatory and antioxidant effects in HaCaT cells exposed to particulate matter. Therefore, negative air ions can be used for the prevention and treatment of particulate matter-related inflammatory skin diseases.

Regulation of Mitochondrial Quality Control by Natural Drugs in the Treatment of Cardiovascular Diseases: Potential and Advantages

Mitochondria are double-membraned cellular organelles that provide the required energy and metabolic intermediates to cardiomyocytes. Mitochondrial respiratory chain defects, structure abnormalities, and DNA mutations can affect the normal function of cardiomyocytes, causing an imbalance in intracellular calcium ion homeostasis, production of reactive oxygen species, and apoptosis. Mitochondrial quality control (MQC) is an important process that maintains mitochondrial homeostasis in cardiomyocytes and involves multi-level regulatory mechanisms, such as mitophagy, mitochondrial fission and fusion, mitochondrial energy metabolism, mitochondrial antioxidant system, and mitochondrial respiratory chain. Furthermore, MQC plays a role in the pathological mechanisms of various cardiovascular diseases (CVDs). In recent years, the regulatory effects of natural plants, drugs, and active ingredients on MQC in the context of CVDs have received significant attention. Effective active ingredients in natural drugs can influence the production of energy-supplying substances in the mitochondria, interfere with the expression of genes associated with mitochondrial energy requirements, and regulate various mechanisms of MQC modulation. Thus, these ingredients have therapeutic effects against CVDs. This review provides useful information about novel treatment options for CVDs and development of novel drugs targeting MQC.

Effects of Particulate Matter in a Mouse Model of Oxazolone-Induced Atopic Dermatitis

BACKGROUND

Recent epidemiological studies have demonstrated that air pollution is associated with the inflammatory response and may aggravate inflammatory skin diseases such as atopic dermatitis (AD). However, it is unclear whether particulate matter (PM) aggravates AD symptoms.

OBJECTIVE

The aim of this study was to investigate whether PM exposure affects the skin barrier dysfunction and aggravates AD symptoms using human keratinocytes (HaCaT) cells and a mouse model of oxazolone-induced AD-like skin.

METHODS

Standard reference material (SRM) 1649b, which mainly comprises polycyclic aromatic hydrocarbons, was used as the reference PM. HaCaT cells and mouse model of oxazolone-induced AD-like skin were treated with PM. The mRNA or protein expression levels of stratum corneum (SC) and tight junction (TJ) proteins, inflammatory cytokines, as well as clinical and histological changes of the AD-like skin of mouse model were evaluated. The expression of genes and proteins was analyzed by real-time polymerase chain reaction and Western blotting. Levels of inflammatory cytokines were measured by enzyme-linked immunosorbent assay.

RESULTS

The results revealed that PM downregulates the expression levels of several SC and TJ-related proteins in the mouse model with AD-like skin. Clinically, epidermal and dermal thickness was significantly increased and dermal inflammation was prominent in PM treated AD-like skin.

CONCLUSION

In conclusion, we found that PM aggravates skin barrier dysfunction, clinically augmenting epidermal and dermal thickening with dermal inflammation in AD-like skin. These results suggest that PM may trigger the exacerbation of AD symptoms via skin barrier dysfunction-related mechanisms.

Eupafolin alleviates cerebral ischemia/reperfusion injury in rats via blocking the TLR4/NF‑κB signaling pathway

Eupatorium perfoliatum L. (E. perfoliatium) has been used traditionally for treating fever, malaria and inflammation‑associated diseases. Eupafolin, the extract of E. perfoliatium, was also reported to suppress inflammation. The present study aimed to investigate the protective effects of eupafolin on cerebral ischemia/reperfusion (I/R) injury in rats and its possible underlying mechanisms. Cerebral I/R injury was induced in rats by middle cerebral artery occlusion (MCAO) for 1.5 h, followed by reperfusion. The rats were randomly assigned into six groups: Control, model, 10 mg/kg eupafolin, 20 mg/kg eupafolin, 50 mg/kg eupafolin and 20 mg/kg nimodipine. Eupafolin and nimodipine were intragastrically administrated to the rats 1 week before MCAO induction. Following reperfusion for 24 h, the neurological deficit was scored, and brain samples were harvested for evaluating encephaledema, infarct volume, oxidative stress, apoptosis, inflammation and the expression of TLR4/NF‑κB signaling. The results revealed that eupafolin decreased the neurological score, relieved encephaledema and decreased infarct volume. Eupafolin also attenuated oxidative stress, neuronal apoptosis and inflammation, with decreases in lactate dehydrogenase, malondialdehyde, TUNEL‑positive cells, Bax and caspase‑3, along with TNF‑α, IL‑1β and IL‑6, but increases in superoxide dismutase and Bcl‑2 levels. Furthermore, eupafolin may decrease the expression of TLR4 downstream proteins and proteins involved in the NF‑κB pathway. Treatment with TLR4 agonist‑LPS significantly blunted the protective effect of eupafolin on encephaledema and cerebral infarct. Meanwhile, 20 mg/kg eupafolin showed nearly equivalent effects to the positive‑control drug nimodipine. In conclusion, eupafolin protected against cerebral I/R injury in rats and the underlying mechanism may be associated with the suppression of apoptosis and inflammation via inhibiting the TLR4/ NF‑κB signaling pathway.

Impact of airborne particulate matter on skin: a systematic review from epidemiology to in vitro studies

BACKGROUND

Air pollution is killing close to 5 million people a year, and harming billions more. Air pollution levels remain extremely high in many parts of the world, and air pollution-associated premature deaths have been reported for urbanized areas, particularly linked to the presence of airborne nano-sized and ultrafine particles.

MAIN TEXT

To date, most of the research studies did focus on the adverse effects of air pollution on the human cardiovascular and respiratory systems. Although the skin is in direct contact with air pollutants, their damaging effects on the skin are still under investigation. Epidemiological data suggested a correlation between exposure to air pollutants and aggravation of symptoms of chronic immunological skin diseases. In this study, a systematic literature review was conducted to understand the current knowledge on the effects of airborne particulate matter on human skin. It aims at providing a deeper understanding of the interactions between air pollutants and skin to further assess their potential risks for human health.

CONCLUSION

Particulate matter was shown to induce a skin barrier dysfunction and provoke the formation of reactive oxygen species through direct and indirect mechanisms, leading to oxidative stress and induced activation of the inflammatory cascade in human skin. Moreover, a positive correlation was reported between extrinsic aging and atopic eczema relative risk with increasing particulate matter exposure.

Resveratrol Inhibits Particulate Matter-Induced Inflammatory Responses in Human Keratinocytes

Particulate matter (PM), a major air pollutant, is a complex mixture of solid and liquid particles of various sizes. PM has been demonstrated to cause intracellular inflammation in human keratinocytes, and is associated with various skin disorders, including atopic dermatitis, eczema, and skin aging. Resveratrol is a natural polyphenol with strong antioxidant properties, and its beneficial effects against skin changes due to PM remain elusive. Therefore, in the present study, we investigated the effect of resveratrol on PM-induced skin inflammation and attempted to deduce the molecular mechanisms underlying resveratrol’s effects. We found that resveratrol inhibited PM-induced aryl hydrocarbon receptor activation and reactive oxygen species formation in keratinocytes. It also suppressed the subsequent cellular inflammatory response by inhibiting mitogen-activated protein kinase activation. Consequentially, resveratrol reduced PM-induced cyclooxygenase-2/prostaglandin E2 and proinflammatory cytokine expression, including that of matrix metalloproteinase (MMP)-1, MMP-9, and interleukin-8, all of which are known to be central mediators of various inflammatory conditions and aging. In conclusion, resveratrol inhibits the PM-induced inflammatory response in human keratinocytes, and we suggest that resveratrol may have potential for preventing air pollution-related skin problems.

Oxidative contribution of air pollution to extrinsic skin ageing

•Epidemiological evidence links exposure to poor air quality to lentigines and wrinkles. •Experimental studies provide mechanistic explanations involving oxidative stress. •Polluted air may hasten skin ageing through indirect systemic effects via the lung and/or direct effects on cutaneous tissue. •Prevention measures would need to combine strategies that target both ‘routes’. •Air pollution is one of several environmental stressors that combined, may have additive/synergistic effects on the skin.

Glycofullerenes Inhibit Particulate Matter Induced Inflammation and Loss of Barrier Proteins in HaCaT Human Keratinocytes

Exposure to particulate matter (PM) has been linked to pulmonary and cardiovascular dysfunctions, as well as skin diseases, etc. PM impairs the skin barrier functions and is also involved in the initiation or exacerbation of skin inflammation, which is linked to the activation of reactive oxygen species (ROS) pathways. Fullerene is a single C₆₀ molecule which has been reported to act as a good radical scavenger. However, its poor water solubility limits its biological applications. The glyco-modification of fullerenes increases their water solubility and anti-bacterial and anti-virus functions. However, it is still unclear whether it affects their anti-inflammatory function against PM-induced skin diseases. Hence, glycofullerenes were synthesized to investigate their effects on PM-exposed HaCaT human keratinocytes. Our results showed that glycofullerenes could reduce the rate of PM-induced apoptosis and ROS production, as well as decrease the expression of downstream mitogen-activated protein kinase and Akt pathways. Moreover, PM-induced increases in inflammatory-related signals, such as cyclooxygenase-2, heme oxygenase-1, and prostaglandin E2, were also suppressed by glycofullerenes. Notably, our results suggested that PM-induced impairment of skin barrier proteins, such as filaggrin, involucrin, repetin, and loricrin, could be reduced by pre-treatment with glycofullerenes. The results of this study indicate that glycofullerenes could be potential candidates for treatments against PM-induced skin diseases and that they exert their protective effects via ROS scavenging, anti-inflammation, and maintenance of the expression of barrier proteins.

Eupafolin ameliorates lipopolysaccharide-induced cardiomyocyte autophagy via PI3K/AKT/mTOR signaling pathway

Objective(s):

Eupafolin, a major active component of Eupatorium perfoliatum L., has anti-inflammatory and anti-oxidant properties. Lipopolysaccharide (LPS) is responsible for myocardial depression. A line of evidences revealed that LPS induces autophagy in cardiomyocytes injury. This study aims to evaluate the effects of eupafolin on LPS-induced cardiomyocyte autophagy.

Materials and Methods:

The effect of LPS on cell viability was examined by CCK-8. Autophagic protein 2 light chain 3 (LC3II), which was regulated by LPS and eupafolin, was examined using immunofluorescent staining. The expression levels of Beclin-1 and p62 were detected by western blotting. The effects of eupafolin on phosphatidylinositol-3-kinase/ protein kinase B/ mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway were also evaluated by western blotting and immunofluorescent staining.

Results:

Eupafolin pretreatment reduced the expression of LC3II and Beclin-1, whereas p62 was significant increased. In addition, eupafolin promoted expression of PI3K/AKT/mTOR signaling pathway and mTOR inhibitor rapamycin reversed the inhibitory effects on LPS-induced cardiomyocyte autophagy.

Conclusion:

Eupafolin exerts anti-autophagy activity via activation of PI3K/AKT/mTOR signaling pathway.

Antiphotoaging effect of boiled abalone residual peptide ATPGDEG on UVB-induced keratinocyte HaCaT cells

Introduction

A previous study has shown that Ala-Thr-Pro-Gly-Asp-Glu-Gly (ATPGDEG) peptide identified from boiled abalone by-products has high antioxidant activities and antihypertensive effect.

Objective

In this study, we further investigated its antiphotoaging activities by ultraviolet B (UVB)-induced HaCaT cells.

Result

UVB irradiation significantly increased the content of intercellular reactive oxygen species (ROS) and the production of matrix metalloproteinases (MMPs) in HaCaT cells and decreased its content of collagen. First, the generation of intercellular ROS was reduced by abalone peptide in UVB-induced HaCaT cells. And activities of MMP-1 and MMP-9 were reduced by abalone peptide in a dose-dependent manner. Furthermore, western blot analysis demonstrated that abalone peptide downregulated the expression of p38, c-Jun N-terminal kinases, and extracellular signal-regulated kinases via mitogen-activated protein kinases (MAPKs) and NF-κB signaling to protect type I pro collagen and DNA damage. Molecular docking simulation confirms that abalone peptide inhibited activities of MMP-1 and MMP-9 by docking their active site, among them N-terminal Ala, C-terminal Gly, and Pro at the third position of N-terminal made a great contribution.

Conclusion and recommendation

Abalone peptide could protect type I procollagen synthesis in UVB-irradiated HaCaT cells, and it is a potential peptide for the treatment of skin photoaging in the future.

Can Plant Phenolic Compounds Protect the Skin from Airborne Particulate Matter?

The skin is directly exposed to the polluted atmospheric environment, and skin diseases, such as atopic dermatitis and acne vulgaris, can be induced or exacerbated by airborne particulate matter (PM). PM can also promote premature skin aging with its accompanying functional and morphological changes. PM-induced skin diseases and premature skin aging are largely mediated by reactive oxygen species (ROS), and the harmful effects of PM may be ameliorated by safe and effective natural antioxidants. Experimental studies have shown that the extracts and phenolic compounds derived from many plants, such as cocoa, green tea, grape, pomegranate, and some marine algae, have antioxidant and anti-inflammatory effects on PM-exposed cells. The phenolic compounds can decrease the levels of ROS in cells and/or enhance cellular antioxidant capacity and, thereby, can attenuate PM-induced oxidative damage to nucleic acids, proteins, and lipids. They also lower the levels of cytokines, chemokines, cell adhesion molecules, prostaglandins, and matrix metalloproteinases implicated in cellular inflammatory responses to PM. Although there is still much research to be done, current studies in this field suggest that plant-derived phenolic compounds may have a protective effect on skin exposed to high levels of air pollution.

Water-Soluble Fullerenol C60(OH)36 toward Effective Anti-Air Pollution Induced by Urban Particulate Matter in HaCaT Cell

Particulate matter (PM), a widespread air pollutant, consists of a complex mixture of solid and liquid particles suspended in air. Many diseases have been linked to PM exposure, which induces an imbalance in reactive oxygen species (ROS) generated in cells, and might result in skin diseases (such as aging and atopic dermatitis). New techniques involving nanomedicine and nano-delivery systems are being rapidly developed in the medicinal field. Fullerene, a kind of nanomaterial, acts as a super radical scavenger. Lower water solubility levels limit the bio-applications of fullerene. Hence, to improve the water solubility of fullerene, while retaining its radical scavenger functions, a fullerene derivative, fullerenol C₆₀(OH)₃₆, was synthesized, to examine its biofunctions in PM-exposed human keratinocyte (HaCaT) cells. The PM-induced increase in ROS levels and expression of phosphorylated mitogen-activated protein kinase and Akt could be inhibited via fullerenol pre-treatment. Furthermore, the expression of inflammation-related proteins, cyclooxygenase-2, heme oxygenase-1, and prostaglandin E2 was also suppressed. Fullerenol could preserve the impaired state of skin barrier proteins (filaggrin, involucrin, repetin, and loricrin), which was attributable to PM exposure. These results suggest that fullerenol could act against PM-induced cytotoxicity via ROS scavenging and anti-inflammatory mechanisms, and the maintenance of expression of barrier proteins, and is a potential candidate compound for the treatment of skin diseases.

Environmental Stressors on Skin Aging. Mechanistic Insights

The skin is the main barrier that protects us against environmental stressors (physical, chemical, and biological). These stressors, combined with internal factors, are responsible for cutaneous aging. Furthermore, they negatively affect the skin and increase the risk of cutaneous diseases, particularly skin cancer. This review addresses the impact of environmental stressors on skin aging, especially those related to general and specific external factors (lifestyle, occupation, pollutants, and light exposure). More specifically, we have evaluated ambient air pollution, household air pollutants from non-combustion sources, and exposure to light (ultraviolet radiation and blue and red light). We approach the molecular pathways involved in skin aging and pathology as a result of exposure to these external environmental stressors. Finally, we reflect on how components of environmental stress can interact with ultraviolet radiation to cause cell damage and the critical importance of knowing the mechanisms to develop new therapies to maintain the skin without damage in old age and to repair its diseases.

Marine Alga Ecklonia cava Extract and Dieckol Attenuate Prostaglandin E2 Production in HaCaT Keratinocytes Exposed to Airborne Particulate Matter

Atmospheric particulate matter (PM) is an important cause of skin damage, and an increasing number of studies have been conducted to discover safe, natural materials that can alleviate the oxidative stress and inflammation caused by PM. It has been previously shown that the extract of Ecklonia cava Kjellman, a perennial brown macroalga, can alleviate oxidative stress in epidermal keratinocytes exposed to PM less than 10 microns in diameter (PM10). The present study was undertaken to further examine the anti-inflammatory effects of E. cava extract and its major polyphenolic constituent, dieckol. HaCaT keratinocytes were exposed to PM10 in the presence or absence of E. cava extract or dieckol and analyzed for their viability, prostaglandin E₂ (PGE₂) release, and gene expression of cyclooxygenase (COX)-1, COX-2, microsomal prostaglandin E₂ synthase (mPGES)-1, mPGES-2, and cytosolic prostaglandin E₂ synthase (cPGES). PM10 treatment decreased cell viability and increased the production of PGE₂, and these changes were partially abrogated by E. cava extract. E. cava extract also attenuated the expression of COX-1, COX-2, and mPGES-2 stimulated by PM10. Dieckol attenuated PGE₂ production and the gene expression of COX-1, COX-2, and mPGES-1 stimulated by PM10. This study demonstrates that E. cava extract and dieckol alleviate airborne PM10-induced PGE₂ production in keratinocytes through the inhibition of gene expression of COX-1, COX-2, mPGES-1, and/or mPGES-2. Thus, E. cava extract and dieckol are potentially useful natural cosmetic ingredients for counteracting the pro-inflammatory effects of airborne PM.

Afzelin suppresses proinflammatory responses in particulate matter-exposed human keratinocytes

Particulate matter (PM), a widespread airborne contaminant, is a complex mixture of solid and liquid particles suspended in the air. Recent studies have demonstrated that PM induces oxidative stress and inflammatory reactions, and may cause certain skin diseases. Afzelin is a flavonoid isolated from Thesium chinense Turcz, which has anti‑inflammatory, anticancer and antibacterial properties. Therefore, the present study aimed to investigate if afzelin affected inflammatory responses in human keratinocytes exposed to PM. HaCaT cells were treated with PM (25 µg/cm2) in the presence or absence of afzelin (200 µM). Here, standard reference material 1649b was used as PM. Cell viability was assessed using the water‑soluble tetrazolium salt‑1 assay. The generation of reactive oxygen species (ROS) was measured using the dichloro‑dihydro‑​fluorescein diacetate assay. Gene and protein expression were investigated using reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. Levels of secreted inflammatory cytokines were measured using ELISA. The results suggested that afzelin inhibited PM‑induced proinflammatory cytokine mRNA expression and protein secretion in HaCaT cells. In addition, afzelin suppressed PM‑induced intracellular ROS generation, and p38 mitogen‑activated protein kinase and transcription factor activator protein‑1 component c‑Fos and c‑Jun activation. The results indicated that afzelin exerts anti‑inflammatory and antioxidant effects in PM‑exposed HaCaT. Afzelin may have potential for preventing PM‑induced inflammatory skin diseases.

Urban particulate matter in air pollution penetrates into the barrier-disrupted skin and produces ROS-dependent cutaneous inflammatory response in vivo

BACKGROUND

Particulate matter (PM) is an integral part of air pollution, which is a mixture of particles suspended in the air. Recently, it has been reported that PM is associated with increased risks of skin diseases, especially atopic dermatitis in children. However, it is unclear if PM directly goes into the skin and what mechanisms are involved in response to PM.

OBJECTIVE

To see whether PM could penetrate into the barrier-disrupted skin, produce reactive oxygen species (ROS), and elicit an inflammatory response.

METHODS

We collected PMs during a winter in Seoul and used cultured keratinocytes for in vitro study and tape-stripped BALB/c mice for in vivo study.

RESULTS

Keratinocyte cytotoxicity increased in a dose-dependent manner by PM treatment. IL-8 and MMP-1 mRNA expression and protein levels were significantly increased compared to control by qPCR and ELISA, respectively. Cellular ROS production was increased by PM treatment, and antioxidant N-acetyl cysteine pretreatment prevented induction of inflammatory cytokines IL-8 and MMP-1. In PM-treated keratinocytes, electron-dense subcellular particles were observed by transmission electron microscopy. PM was observed inside hair follicles in both intact and barrier-disrupted skin in vivo. Additionally, intercellular penetration of PM was seen in the barrier-disrupted skin. Repeated PM application induced epidermal thickening and dermal inflammation with neutrophil infiltration. Finally, N-acetyl cysteine could ameliorate skin inflammation induced by PM application.

CONCLUSION

PM penetrates into the barrier-disrupted skin, causing inflammation, demonstrating detrimental effects in the skin.

Nepetin inhibits IL-1β induced inflammation via NF-κB and MAPKs signaling pathways in ARPE-19 cells

BACKGROUNDS

Chronic inflammation in retinal pigment epithelial (RPE) cells is related to the pathogenesis of retinal inflammatory blind causing diseases such as age-related macular degeneration (AMD) and diabetic retinopathy (DR). Nepetin, a natural flavonoid compound, has shown potent anti-inflammatory activities but has not been studied on ocular resident cells yet. Here, we assess the ability of Nepetin to alleviate the inflammatory responses of ARPE-19 cells induced by interleukin (IL)-1β.

METHODS

The secretion and mRNA expression of inflammatory cytokines IL-6, IL-8 and monocyte chemoattractant protein-1 (MCP-1) induced by IL-1β are measured by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR) respectively. To clarify the underlying action mechanism, we examine the effect of Nepetin on activation of nuclear factor of kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways using Western blot.

RESULTS

Nepetin can significantly decrease the three inflammatory mediators at both protein and mRNA level in a dose-dependent manner. Western blot results show that Nepetin can decrease the nuclear translocation of p65 through suppressing phosphorylation of inhibitor of nuclear factor kappa B (IκB) and IκB kinase (IKK). Also, Nepetin can decrease the phosphorylation of extracellular signal-regulated kinases (ERK) 1/2, c-Jun N-terminal kinase (JNK) and p38 MAPK.

CONCLUSIONS

Taken together, Nepetin abolishes IL-1β-induced IL-6, IL-8 and MCP-1 secretion and mRNA expression by repressing the activation of NF-κB and MAPKs. These results indicate that Nepetin shows potential to be used for prevention and treatment of inflammatory retinal diseases or as a lead compound.

PM2.5 exposure stimulates COX-2-mediated excitatory synaptic transmission via ROS-NF-κB pathway

Long-term exposure to fine particulate matter (PM_2.5) has been reported to be closely associated with the neuroinflammation and synaptic dysfunction, but the mechanisms underlying the process remain unclear. Cyclooxygenase-2 (COX-2) is a key player in neuroinflammation, and has been also implicated in the glutamatergic excitotoxicity and synaptic plasticity. Thus, we hypothesized that COX-2 was involved in PM_2.5-promoted neuroinflammation and synaptic dysfunction. Our results revealed that PM_2.5 elevated COX-2 expression in primary cultured hippocampal neurons and increased the amplitude of field excitatory postsynaptic potentials (fEPSPs) in hippocampal brain slices. And the administration of NS398 (a COX-2 inhibitor) prevented the increased fEPSPs. PM_2.5 also induced intracellular reactive oxygen species (ROS) generation accompanied with glutathione (GSH) depletion and the loss of mitochondrial membrane potential (MMP), and the ROS inhibitor, N-acetyl-L-cystein (NAC) suppressed the COX-2 overexpression and the increased fEPSPs. Furthermore, the nuclear factor kappa B (NF-κB) was involved in ROS-induced COX-2 and fEPSP in response to PM_2.5 exposure. These findings indicated that PM_2.5 activated COX-2 expression and enhanced the synaptic transmission through ROS-NF-κB pathway, and provided possible biomarkers and specific interventions for PM_2.5-induced neurological damage.